Glasgow Coma Scale (GCS) is a neurological scale which aims to give a reliable and objective way of determine a patient’s level of consciousness for initial as well as subsequent assessment .This avoids the need to make arbitrary distinctions between consciousness and different levels of coma. Brain injury is often classified as severe (GCS less than 8), moderate (GCS 9 till 12) and mild (GCS more than 13).
GCS was initially used to assess level of consciousness after head injury and the scale is now used by first responders, EMS, nurses, and doctors as being applicable to all acute medical and traumatic patients. In hospitals, it is also used in monitoring chronic patients in intensive care. The GCS was developed as a simple, objective assessment of impaired consciousness and coma and is based on eye opening, verbal and motor responsiveness (Teasdale ; Jennett, 1974).
Its straightforward approach by nursing, medical and other staff and use of simple terms to record and communicate their findings, the scale became an integral part of the care of patients with acute brain injury from head trauma, intracranial haemorrhage and many other causes. The GCS reflects the initial severity of brain dysfunction, while serial assessments demonstrate the evolution of the injury. Each is crucial for decision making. The GCS is also a guide to prognosis and an essential tool for research studies. Four decades after its introduction, the GCS has gained worldwide acceptance (Teasdale et al., 2014). It is now employed in more than 80 countries, has been translated into more than 60 languages and there are more than 18,000 references to its use (Middleton, 2012).
Glasgow Coma Scale
1 2 3 4 5 6
Eye Does not open eyes Opens eyes in response to painful stimuli
Opens eyes in response to voice Opens eyes spontaneously N/A N/A
Verbal Makes no sounds Incomprehensible sounds Utters incoherent words Confused, disoriented Oriented, converses normally N/A
Motor Makes no movements Extension to painful stimuli (decerebrate response)
Abnormal flexion to painful stimuli (decorticate response)
Flexion / Withdrawal to painful stimuli Localizes to painful stimuli Obeys commands
ADVANTAGES OF GLASGOW COMA SCALE (GCS)
The advantage of Glasgow Coma Scale GCS is most widely recognised of all conscious level scoring systems in the world. It has since been adapted for widespread use based on its relative simplicity and association with prognosis and has been further modified for use in the pediatric population (Holmes et al., 2005). GCS is one of the most effective and prevalent scoring technique to describe the level of consciousness and help to note trends in a patient response to stimuli. GCS is a neurological assessment scale which aims to give a reliable, objective way of recording the conscious state of a person, for initial as well as subsequent assessment (Falk A, Alm A ; Lindstrom V. 2014).
Other than that, GCS reproducible by well-trained staff. The challenge for the critical nurse includes the quick decision of acute events to ensure high levels of patient safety. It is therefore important that nursing staff, those working in critical care setting should be competent to have efficient assessment and evaluation skills to deal and manage their patient especially those with disturbed level of consciousness (Singh ; et al ,2016). Nurse’s managers and educators should develop educational programs provided to all nurses caring for unconscious patient to increase and update their knowledge and skills concerning GCS technique.
A number of studies have explored the use of the GCS by nurses. An exploring third year student nurses understanding of the GCS, revealed a lack of confidence in 62% of the student nurses who were interviewed, this is despite the use of the GCS being a core component in most pre-registration nursing curricula (Shoqirat, 2006). In a more recent study concurs with Shoqirat, finding a significant positive correlation between nurses’ attitudes and nurses self-confidence in using the GCS, length of time spent in nursing, working in a neuroscience setting and a more positive attitude towards the GCS affected nurses’ self-confidence in using the GCS (Mattar et al.,2015). The evidence cited suggests that should nurses not be experienced or undergo education that is of sufficient depth, then the consistency and accuracy of scoring is questionable.
GCS is Line in the fast lane (LITFL) mention that it has “face validity”. The advantages of the GCS are that it has face validity, wide acceptance, and established statistical associations with adverse neurologic outcome including brain injury, neurosurgical intervention, and mortality (Zuercher M et al, 2009). This issue is complicated further when the GCS is used outside of neuroscience settings. Crossman et al. (1998) revealed that the GCS was used inaccurately by non-neurological and neurosurgical doctors who incorrectly opted for the lowest possible scores. These physicians were experienced and indicated that the correct use of the GCS is not isolated to the degree of experience, but also the degree of knowledge, and possibly relates to how they were educated in the use of the GCS. GCS also quick to use or applied for the patient. Quick neurologic assessment for prognosis and victim’s ability to maintain patent airway on own.
DISADVANTAGES OF THE GLASGOW COMA SCALE (GCS)
The disadvantage of GCS is not reliable. To be accurate and useful, a clinical scale must be reproducible. Unfortunately, the GCS contains multiple subjective elements and has repeatedly demonstrated surprisingly low interrater reliability in a variety of settings (Steele R, et al.,2005). In a study of independent paired assessments by attending emergency physicians, for example, GCS scores were the same in just 38% and were 2 or more points apart in 33%. Thus, the underlying precision of this tool is overstated by its 13 possible gradations, and any reported value should be considered as having an error margin of multiple adjacent points. The reliability of the GCS is further compromised in tracheal intubated patients because verbal response can no longer be evaluated.
Other than that, GCS is not consistently remembered. To be accurately and consistently applied, a clinical scale must be easy to use and remember. The GCS is widely perceived as complicated and takes more than just a few seconds to evaluate (Goldhill DR ,2004). In one study, only 15% of military physicians could correctly calculate the GCS, despite all of them being familiar with the scale and most having completed the advanced trauma life support course (Brown W, et al ,2005). A second report observed that less than half (48%) of clinicians correctly scored the GCS in a written clinical scenario with neurosurgeons correct just 56% of the time (Punt Ja, et al.,1999).
According to Brain Injury Association (2015), GCS does not work as well if healthcare providers cannot score all 3 parts of the test. Healthcare providers cannot score the person’s verbal responses if firstly, he drank alcohol before his injury and alcohol may make his speech hard to understand. Secondly, he has an endotracheal (ET) tube in his throat to help him breathe because the ET tube makes talking difficult and the lase one the person was given medicine to decrease pain or swelling because the medicine may make him too sleepy to talk. Healthcare providers cannot score how well the person opens his eyes if his eyes are swollen shut from the injury. Other than that, healthcare providers cannot score the person’s body movements if an injury causes pain with movement, or makes the person unable to move. Glascow coma scale cannot be applied to small children. GCS as an objective assessment of neurological function, is of limited usefulness in children under 3 years of age. One the component of GCS is the best verbal response which cannot be assessed in nonverbal small children. A modification of the original GCS was created for children too young to talk.
Although initially described four decades ago, the GCS approaches to assessment of initial severity and outcome of brain damage have weathered the test of time. It remains the standard for acute assessment. GCS is very important in neurologic assessment to the patient regarding:
The GCS is the most familiar, most widely-used early assessment of level of consciousness. It has established categories related to the presence of coma and severity of injury.
A very brief, simple observer rated scale. The application of painful stimulus is controversial. Assessment of all components is compromised by aggressive, early interventions such as intubation and sedation.
The scale is simple to administer and designed for use by any health profession. Lack of experience and variability in assessment may result in inaccurate assessment. Training and standardized procedures are recommended.